Reduce signal sender thread stack size to 32k.

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
===================================================================
--- src/platform-openbsd.cc	(revision 10368)
+++ src/platform-openbsd.cc	(working copy)
@@ -146,7 +146,7 @@
 
 // We keep the lowest and highest addresses mapped as a quick way of
 // determining that pointers are outside the heap (used mostly in assertions
-// and verification).  The estimate is conservative, ie, not all addresses in
+// and verification).  The estimate is conservative, i.e., not all addresses in
 // 'allocated' space are actually allocated to our heap.  The range is
 // [lowest, highest), inclusive on the low and and exclusive on the high end.
 static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
@@ -512,18 +512,11 @@
 
 Thread::Thread(const Options& options)
     : data_(new PlatformData()),
-      stack_size_(options.stack_size) {
-  set_name(options.name);
+      stack_size_(options.stack_size()) {
+  set_name(options.name());
 }
 
 
-Thread::Thread(const char* name)
-    : data_(new PlatformData()),
-      stack_size_(0) {
-  set_name(name);
-}
-
-
 Thread::~Thread() {
   delete data_;
 }
@@ -789,8 +782,10 @@
     FULL_INTERVAL
   };
 
+  static const int kSignalSenderStackSize = 32 * KB;
+
   explicit SignalSender(int interval)
-      : Thread("SignalSender"),
+      : Thread(Thread::Options("SignalSender", kSignalSenderStackSize)),
         vm_tgid_(getpid()),
         interval_(interval) {}